US4120567A
Expired / Lapsed
US
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Electro-optic device
Assignee: RCA Corp
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Filing: 1977-02-11
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Granted: 1978-10-17
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Expires: 1997-02-11
Abstract
Abstract Liquid crystal mixtures of liquid crystalline esters, biphenyls and terphenyls have wide useful temperature ranges, fast response times and a small index of refraction anisotropy which can be employed in liquid crystal cells having improved viewing angles.
Inventors
- 👤 Lawrence Alan Goodman
- 👤 Aaron William Levine
- 👤 Dietrich Meyerhofer
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 15:55
CPC Classifications
C; C09; C09K; C09K19/00; C09K19/04; C09K19/42; C09K19/46
Claims Analysis
Total Claims: 4
Claim 1
Independent Claim
168 words
An electro-optic device having an improved viewing angle comprising a nematic liquid crystal composition between two electrodes, wherein the liquid crystal composition has an index of refraction anisotropy of less than 0.23 and contains a mixture of at least one compound from each of the following groups of liquid crystal compounds (1) a liquid crystal ester having the formula ##STR5## wherein R is an alkyl group of 4 to 10 carbon atoms; (2) a liquid crystal diester having the formula ##STR6## wherein R 1 at each occurrence is an alkyl group of 1 to 10 carbon atoms, and X at each occurrence is hydrogen or a methyl group with the proviso that at least one X is methyl; (3) a liquid crystal biphenyl having the formula ##STR7## wherein R 2 is an alkyl or alkoxy group of 3 to 8 carbon atoms; and (4) a liquid crystal terphenyl compound having the formula ##STR8## wherein R 3 is an alkyl or alkoxy group of 4 to 6 carbon atoms.
Claim 2
Dependent Claim
168 words
An electro-optic device having an improved viewing angle comprising a nematic liquid crystal composition between two electrodes, wherein the liquid crystal composition has an index of refraction anisotropy of less than 0.23 and contains a mixture of at least one compound from each of the following groups of liquid crystal compounds (1) a liquid crystal ester having the formula ##STR5## wherein R is an alkyl group of 4 to 10 carbon atoms; (2) a liquid crystal diester having the formula ##STR6## wherein R 1 at each occurrence is an alkyl group of 1 to 10 carbon atoms, and X at each occurrence is hydrogen or a methyl group with the proviso that at least one X is methyl; (3) a liquid crystal biphenyl having the formula ##STR7## wherein R 2 is an alkyl or alkoxy group of 3 to 8 carbon atoms; and (4) a liquid crystal terphenyl compound having the formula ##STR8## wherein R 3 is an alkyl or alkoxy group of 4 to 6 carbon atoms.
Claim 3
Dependent Claim
153 words
A liquid crystal composition having an index of refraction anisotropy from about 0.17 to about 0.23 which comprises a mixture of at least one compound from each of the following groups of liquid crystal compounds: (1) a liquid crystal ester having the formula ##STR9## wherein R is an alkyl group of 4 to 10 carbon atoms; (2) a liquid crystal diester having the formula ##STR10## wherein R 1 at each occurrence is an alkyl group of 1 to 10 carbon atoms, and X at each occurrence is hydrogen or a methyl group with the proviso that at least one X is methyl; (3) a liquid crystal biphenyl compound having the formula ##STR11## wherein R 2 is an alkyl or alkoxy group of 3 to 8 carbon atoms; and (4) a liquid crystal terphenyl compound having the formula ##STR12## wherein R 3 is an alkyl or alkoxy group of 4 to 6 carbon atoms.
Claim 4
Dependent Claim
153 words
A liquid crystal composition having an index of refraction anisotropy from about 0.17 to about 0.23 which comprises a mixture of at least one compound from each of the following groups of liquid crystal compounds: (1) a liquid crystal ester having the formula ##STR9## wherein R is an alkyl group of 4 to 10 carbon atoms; (2) a liquid crystal diester having the formula ##STR10## wherein R 1 at each occurrence is an alkyl group of 1 to 10 carbon atoms, and X at each occurrence is hydrogen or a methyl group with the proviso that at least one X is methyl; (3) a liquid crystal biphenyl compound having the formula ##STR11## wherein R 2 is an alkyl or alkoxy group of 3 to 8 carbon atoms; and (4) a liquid crystal terphenyl compound having the formula ##STR12## wherein R 3 is an alkyl or alkoxy group of 4 to 6 carbon atoms.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1981-10-16 | 1982-04-17 | 1982-10-17 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1985-10-16 | 1986-04-17 | 1986-10-17 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1989-10-16 | 1990-04-17 | 1990-10-17 | $7700.00 | Window Closed / Lapsed |